"Actually Carrera, you could have even cracked his skull and get away with it cuz he would have had lock cutters.."
The ideal would be to wait till the thief is on the bike and just started to pedal off. It would then be a matter of grabbing the rear fork and throwing the bike over so the thief hits the floor hard.
After that, you just keep him there and have someone call the Police.
At any rate, I've had no calls from the Police yet so it seems maybe they've not analysed the security tapes. In reality, this case should be a cakewalk. Any city camera should pick up a guy carrying bolt croppers who meets the description we already have.